The present application relates to the monitoring of pressure vessels. More particularly, the present application relates to transducing malfunctions in flow control such as leaky valves, stuck valves, liquid or gas phases, or multiple phases associated with flow control in pressure vessels.
Steam traps are commonly used in many industries to remove condensate from steam lines. In a typical plant, thousands of such devices may be deployed. A steam trap is generally a relatively low technology device that is designed to be relatively inexpensive. Often, steam traps are completely mechanical. Adding any electrical wiring for either powering or wiring would be considered cost prohibitive, impractical or labor intensive.
A steam trap is generally designed to allow condensate to escape a steam pipe in order to maintain efficiency and prevent pipe “knocking”. A typical steam trap may have one or more chambers and a movable member that is in physical contact with the condensate. As the level of condensate rises above some threshold, the movable member within the steam trap actuates or otherwise engages one or more valves to allow at least some of the condensate to escape. As the condensate escapes, the level of condensate within the steam trap is reduced to such an extent that the valve is closed.
Malfunctioning steam traps can leak steam which wastes energy or can fail to remove condensate properly. In many instances, the malfunction is not detected by plant control systems and is therefore unknown to plant personnel for extended periods of time.
Other types of flow control devices associated with pressure vessels such as control valves, orifices, nozzles and restrictions are subject to malfunctions.